Like the tissue test, the urea breath test makes use of the fact that H. Pylori secretes urease, which converts urea into ammonia, producing carbon dioxide as it does so. You are asked to eat nothing for 12 hours before a breath test and are then given a drink containing urea to which a tiny amount of perfectly safe radiation has been added. Thirty minutes later, a small breath sample is collected. If H. pylori is present in your stomach, the urea is converted into ammonia and carbon dioxide, which is then absorbed and excreted in your breath, along with a tiny amount of radioactivity. This can then be measured With a special machine in the hospital laboratory.
The advantage of the breath test is that it is very straightforward and takes a very short amount of time. Like the biopsy urease test, it is very accurate and confirms that you have active H. pylori infection present at the dine of the test. This also means that, if necessary, the breath test can be performed repeatedly to check whether the bacteria have been eradicated after treatment. The disadvantage of the test, like some other H. pylori tests, is that the result may be inaccurate if you are taking proton pump inhibitor medication. Also the result is not usually available for several days because of the measuring equipment used.
Antibody Blood Test
As with other infections, H. pylori infection trigger the production of specific antibodies in your blood. These can then be looked for with a simple blood test and the presence of these antibodies confirms H. pylori infection. Once your body has produced these antibodies they may persist for many years even after the infection has been eradicated.
For this reason, the blood test is useful for diagnosing infection only in a person who has never had H. pylori treatment, and it cannot be used more than once. The real advantage of the test is that it is very quick and usually available in the GP’s surgery. Unlike the other tests for H. pylori, any drugs that you may be taking do not influence the blood test.